1. Field of the Invention
This invention relates to the interconnection of a plurality of electrical conductors such as discrete insulated wires, ribbon cable conductors, flat cable conductors, or the interconnection of a wire or cable to an electrically conductive terminal. This invention also relates to the interconnection of conductors using polymeric electrically conductive materials to form the interconnection.
2. Description of the Prior Art
Polymeric electrically conductive materials, such as conductive epoxies and thermoplastic adhesives, have been used, though perhaps not extensively, to establish interconnections of electrical circuitry. For example, conductive epoxies have been employed to mount electrical components on printed circuit boards. Polymeric electrically conductive adhesives have also been employed in tape form to interconnect conductors on a substrate with other components or circuitry. When used to establish such electrical interconnections, these conductive epoxies and conductive adhesives can be deposited on a surface in a conventional manner, such as by screen printing. Then upon the application of heat and pressure or upon the application of pressure, depending upon the precise character of the conductive adhesive, both electrical and structural or mechanical integrity can be established between separate conductors.
The application of heat to make an electrical interconnection is not limited to use with a conductive adhesive or conductive epoxy. For example, U.S. Pat. No. 3,525,799 discloses a heat recoverable connector formed from a heat shrinkable tubular member containing a fusible insert. That patent discloses the use of a dimensionally heat unstable recoverable sleeve with an internal ring of solder deposited therein. The ends of electrical conductors can be positioned within the solder ring and the entire assembly heated so that the sleeve shrinks and the solder melts to join the two conductors. The sleeve then protects the electrical interconnection formed by the solder. U.S. Pat. No. 4,283,596 discloses a similar electrical connector employing a heat shrinkable sleeve and a fusible solder insert. Each of these patents essentially shows a splice interconnection device. In both instances, once the splice has been made by the application of heat to cause the solder to flow into contact with the conductors and to cause the outer sleeve to shrink, the interconnection will become permanent. These devices offer no opportunity to verify or test the circuit before a permanent interconnection is made.
U.S. Pat. No. 3,538,240 discloses an electrical connector in which a heat shrinkable material is used in conjunction with spring biased contacts. This connector does permit interconnections to be checked prior to the application of heat to the body of the housing. This device, however, relies upon a combination of the spring loading of the individual terminals and the force which could be exerted by the housing material after shrinkage. Fusion of the conductors, by use of a fusible and solder insert such as that shown in U.S. Pat. No. 3,538,240, in part because of the lack of resiliency of solder material. The instant invention not only permits the verification of electrical continuity within a circuit, before the interconnections are made, but also forms a bonded interconnection between the conductors. This invention is also especially adapted to sealing the interconnection between conductors from the environment.